Repairing HP41CX key



#9

Can anyone advise me on repairing the "4" key on my HP41CX. It functions but has lost it's usual snap feel. Or, can someone refer my me to a previous post. Thanks.


#10

Generally, once a key looses its snap... its all over. Nothing will get it back. The metal disk that forms the top of the key contact becomes fatigued. The key still works but the click... she be gone.

The HP41 keyboard is not designed to be repairable (at least not without causing more damage to the machine than you are trying to repair). Keys that double space or do not always give an entry when pressed are easily fixed by cleaning them out with a tiny wire brush (through the plated through hole beneath each key).

That said, sometimes the click problem can be caused by something spilled on the keyboard or a battery leakage problem. But this affects many keys at once.


#11

This ain't my expertise (so what am I doing here, anyway???), I'm more of a 48-kinda-guy. But would it be possible to use "User" to _reassign_ the 4 to another key?

http://www.hpmuseum.org/41cv.jpg suggests maybe [Gold] [+] would be the only easy choice (and lose the [x .LE. y?] functionality to a CATalog).

Well, maybe *would it be worth it* would be a better question, but whatever, just my 0.02_$....


#12

Yes, the keyboard is (almost) fully assignable, and if this could help immediately to go on using the calculator, I don't think that this is a good solution in the long term.

Yes, the keybaord is almost unrepairable. Me recommandation would be to nuy a dear 41 on ebay (you sometimes find some for $30-$40) or post an ad here and switch the upper part of the calc : 5 minutes job.

#13

It's not a disaster. I thing the problem comes from a plastic pin under the key or a metal disc on the printed board. I often fixed that.


#14

How do you fix it? Any pointers about removing the circuit board under the key pad. Aloha.


#15

1. Remove the 4 rubber feet
2. Unscrew the 4 screws
Now you have 3 major parts: front part of HP-41, a middle "U" and the back.
3. If you have a "Fullnut", please remove the board with electronic components, the black plastic sheet, the i/o part between the previous board and the printed board.
You have in front of you 48 pins.
4.Clip them all
5. Lift the printed board up
You have now access to the key and/or the metal disc.


#16

Yes I can do that easily. The problems is how do reattach the printed circuit board to the top half of the case. The heat swaged pins are now gone. Please any solutions.


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